The term "Order Anacanthini" refers to a group of fish without spines in their fins. Alternatively, this group of fish is also called the "Order Atheriniformes". Other synonyms for this term include "thick-lipped fish", "spiny-finned fish", and "spineless fish". These fish are commonly found in freshwater environments such as rivers and lakes, but some species can also be found in marine environments. Some well-known examples of Anacanthini fish include the guppy, the killifish, and the topminnow. While these fish may not have spines in their fins, they still exhibit a wide range of diverse adaptations and behaviors that make them fascinating and important members of aquatic ecosystems.